On Wed, Nov 26, 2014 at 09:39:36PM +0100, Sebastian Andrzej Siewior wrote:
> the following error pops up during "testusb -a -t 10"
> | musb-hdrc musb-hdrc.1.auto: dma_pool_free buffer-128,
> f134e000/be842000 (bad dma)
> hcd_buffer_create() creates a few buffers, the smallest has 32 bytes of
> size. ARCH_KMALLOC_MINALIGN is set to 64 bytes. This combo results in
> hcd_buffer_alloc() returning memory which is 32bytes aligned and it
> might by identified by buffer_offset() as another buffer. This means the
> buffer which is on a 32byte boundary will not get freed, instead it
> tries to free another buffer with the error message.
>
> This patch fixes the issue by creating the smallest DMA buffer with the
> size of ARCH_DMA_MINALIGN. This will be either 32 or 64 bytes. If the
> ARCH_DMA_MINALIGN is 128 (currently powerpc64, mips ip32, x86 pentium 4) then
> it will create the first buffer with 128 bytes and will have only 3
> buffers. There is a BUILD_BUG_ON() now in case someone has a minalign of
> more than 128 bytes.
>
> Cc: sta...@vger.kernel.org
> Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
> Acked-by: Alan Stern <st...@rowland.harvard.edu>
> ---
> v1…v2: rewrite pool_max so it is less confusing.
>
> drivers/usb/core/buffer.c | 12 ++++++++----
> include/linux/usb/hcd.h | 8 ++++++--
> 2 files changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
> index 684ef70dc09d..5ad5f71d6358 100644
> --- a/drivers/usb/core/buffer.c
> +++ b/drivers/usb/core/buffer.c
> @@ -26,10 +26,13 @@ static const size_t pool_max[HCD_BUFFER_POOLS] = {
> /* platforms without dma-friendly caches might need to
> * prevent cacheline sharing...
> */
> - 32,
> - 128,
> - 512,
> - PAGE_SIZE / 2
> +#if ARCH_KMALLOC_MINALIGN <= 32
> + 32, 128, 512, PAGE_SIZE / 2,
> +#elif ARCH_KMALLOC_MINALIGN <= 64
> + 64, 128, 512, PAGE_SIZE / 2,
> +#else
> + 128, 512, PAGE_SIZE / 2
> +#endif
G> /* bigger --> allocate pages */
> };
>
> @@ -58,6 +61,7 @@ int hcd_buffer_create(struct usb_hcd *hcd)
> !(hcd->driver->flags & HCD_LOCAL_MEM))
> return 0;
>
> + BUILD_BUG_ON(ARCH_KMALLOC_MINALIGN > 128);
> for (i = 0; i < HCD_BUFFER_POOLS; i++) {
> size = pool_max[i];
> if (!size)
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index cd96a2bc3388..1e2234ca448d 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -23,6 +23,7 @@
>
> #include <linux/rwsem.h>
> #include <linux/interrupt.h>
> +#include <linux/slab.h>
>
> #define MAX_TOPO_LEVEL 6
>
> @@ -171,8 +172,11 @@ struct usb_hcd {
> struct usb_hcd *shared_hcd;
> struct usb_hcd *primary_hcd;
>
> -
> -#define HCD_BUFFER_POOLS 4
> +#if ARCH_KMALLOC_MINALIGN <= 64
> + #define HCD_BUFFER_POOLS 4
> +#else
> + #define HCD_BUFFER_POOLS 3
> +#endif
> struct dma_pool *pool[HCD_BUFFER_POOLS];
>
> int state;
This breaks the build so badly, it's obvious you never tested it out.
never do that again.
greg k-h
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